oc 类型判断

#import <UIKit/UIKit.h>
#import "AppDelegate.h"
 
@interface A : NSObject
 
@end
 
@implementation A
 
@end
 
@interface AA : A
 
@end
 
@implementation AA
 
@end
 
@interface B : NSObject
 
@end
 
@implementation B
 
@end
 
int main(int argc, char * argv[]) {
    A *a=[[A alloc]init];
    NSLog(@"%d",[a isKindOfClass:[B class ] ]);//返回值1表示是这个类型，0不是这个类型
}